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RFC 1850 - 3.8. OSPF Interface Metrics

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### 3.8. OSPF Interface Metrics

    --  OSPF Interface Metric Table

    --      The Metric Table describes the metrics to be advertised
    --      for a specified interface at the various types of service.
    --      As such, this table is an adjunct of the OSPF Interface
    --      Table.

    -- Types of service, as defined by RFC 791, have the ability
    -- to request low delay, high bandwidth, or reliable linkage.

    -- For the purposes of this specification, the measure of
    -- bandwidth

    --      Metric = 10^8 / ifSpeed

    -- is the default value.  For multiple link interfaces, note
    -- that ifSpeed is the sum of the individual link speeds.
    -- This yields a number having the following typical values:

    --      Network Type/bit rate   Metric

    --      >= 100 MBPS                 1
    --      Ethernet/802.3             10
    --      E1                         48
    --      T1 (ESF)                   65
    --       64 KBPS                 1562
    --       56 KBPS                 1785
    --       19.2 KBPS               5208
    --        9.6 KBPS              10416

    -- Routes that are not specified use the default (TOS 0) metric

        ospfIfMetricTable OBJECT-TYPE
            SYNTAX   SEQUENCE OF OspfIfMetricEntry
            MAX-ACCESS   not-accessible
            STATUS   current
            DESCRIPTION
               "The TOS metrics for  a  non-virtual  interface
               identified by the interface index."
           REFERENCE
              "OSPF Version 2, Appendix C.3  Router  interface
              parameters"
          ::= { ospf 8 }

        ospfIfMetricEntry OBJECT-TYPE
            SYNTAX   OspfIfMetricEntry
            MAX-ACCESS   not-accessible
            STATUS   current
            DESCRIPTION
               "A particular TOS metric for a non-virtual  in-
               terface identified by the interface index."
           REFERENCE
              "OSPF Version 2, Appendix C.3  Router  interface
              parameters"
          INDEX { ospfIfMetricIpAddress,
      ospfIfMetricAddressLessIf,
      ospfIfMetricTOS }
          ::= { ospfIfMetricTable 1 }

    OspfIfMetricEntry ::=
        SEQUENCE {
            ospfIfMetricIpAddress
                IpAddress,
            ospfIfMetricAddressLessIf
                Integer32,
            ospfIfMetricTOS
                TOSType,
            ospfIfMetricValue
                Metric,
            ospfIfMetricStatus
                RowStatus
                  }

        ospfIfMetricIpAddress OBJECT-TYPE
            SYNTAX   IpAddress
            MAX-ACCESS   read-only
            STATUS   current
            DESCRIPTION
               "The IP address of this OSPF interface.  On row
               creation,  this  can  be  derived  from the in-
               stance."
           ::= { ospfIfMetricEntry 1 }

        ospfIfMetricAddressLessIf OBJECT-TYPE
            SYNTAX   Integer32
            MAX-ACCESS   read-only
            STATUS   current
            DESCRIPTION
               "For the purpose of easing  the  instancing  of
               addressed   and  addressless  interfaces;  This
               variable takes the value 0 on  interfaces  with
               IP  Addresses, and the value of ifIndex for in-
               terfaces having no IP Address.   On  row  crea-
               tion, this can be derived from the instance."
           ::= { ospfIfMetricEntry 2 }

        ospfIfMetricTOS OBJECT-TYPE
            SYNTAX   TOSType
            MAX-ACCESS   read-only
            STATUS   current
            DESCRIPTION
               "The type of service metric  being  referenced.
               On  row  creation, this can be derived from the
               instance."
           ::= { ospfIfMetricEntry 3 }

        ospfIfMetricValue OBJECT-TYPE
            SYNTAX   Metric
            MAX-ACCESS   read-create
            STATUS   current
            DESCRIPTION
               "The metric of using this type  of  service  on
               this interface.  The default value of the TOS 0
               Metric is 10^8 / ifSpeed."
           ::= { ospfIfMetricEntry 4 }

        ospfIfMetricStatus OBJECT-TYPE
            SYNTAX   RowStatus
            MAX-ACCESS   read-create
            STATUS   current
            DESCRIPTION
               "This variable displays the status of  the  en-
               try.  Setting it to 'invalid' has the effect of
               rendering it inoperative.  The internal  effect
               (row removal) is implementation dependent."
           ::= { ospfIfMetricEntry 5 }

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RFC 1850 - 3.8. OSPF Interface Metrics